The present invention relates to a data processing device, in particular an electronic memory component, comprising a plurality of access-secured sub-areas, in particular a plurality of access-secured memory areas, each having at least one assigned parameter (an, an−1, . . . , a1, a0), in particular address.
The present invention further relates to a method of encrypting at least one parameter (an, an−1, . . . , a1, a0), in particular the address, of at least one access-secured sub-area, in particular at least one access-secured memory area, of at least one data processing device, in particular at least one electronic memory component.
In known methods of encrypting confidential data, such as personal data, key data or otherwise sensitive data, a non-volatile memory unit can only be encrypted as a complete physical memory in a generally fixed manner; this means that access can only be denied to memories in their entirety.
This method, known from the prior art, of encrypting entire integrated circuit (IC) areas is considered disadvantageous in view of the high cost together with its technical complexity and lack of flexibility. For this reason, it is desirable to develop alternative methods of encrypting access-secured memory areas or sub-areas.
If, for instance, to control a memory of the size M=2i=2n+1 with i=n+1 address buses, when these address buses are encrypted over the entire address space, modification of one address bus would have the possible effect of modifying a plurality of address buses, indeed even those address buses which ensure that a physically remote memory cell is addressed.
This is not sensible for a number of a memory types, including in particular memories that are organized into areas, such as erasable programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM) or Flash memory. Separation of the address buses into a number of areas and subsequent independent encryption of each of the individual areas is inadequate, however, with regard to security.
Taking as basis the above-described disadvantages and shortcomings and acknowledging the outlined prior art, it is an object of the present invention to develop a data processing device, in particular an electronic memory component, of the above-mentioned type, together with an encryption method related thereto, that the security of the device is increased considerably and the expense associated therewith and the technical complexity are not too great.